Here's a breakdown:

* Sun: The Sun formed approximately 4.603 billion years ago.

* Earth: The Earth formed shortly after the Sun, around 4.54 billion years ago.

* Moon: The prevailing scientific theory is that the Moon formed about 4.51 billion years ago, likely from a collision between the early Earth and a Mars-sized object.

Therefore, the Sun is the oldest of the three, followed by Earth and then the Moon.